What this calculator measures
Return on ad spend divides attributed revenue by advertising spend. A 4.0× ROAS means the attribution system assigns four dollars of revenue for each dollar of ad spend. It is a revenue-efficiency measure, not a complete profit measure.
Attribution can materially change the result. Platforms may claim the same conversion, use different lookback windows, or include view-through activity. Use a consistent attribution method when comparing campaigns and reconcile platform reports with business-level sales where possible.
Common use cases
Use this model when the inputs describe the same decision, period and customer or product scope.
- Compare attributed revenue with advertising spend for a campaign or channel.
- Check a break-even ROAS after accounting for gross margin, fees, refunds and fulfillment cost.
- Use attribution-consistent results alongside CAC and customer quality before scaling spend.
Formula
ROAS measures revenue efficiency, while contribution also accounts for the modeled cost of fulfilling sales.
Formula breakdown
- Attributed revenue and ad spend must use the same campaign scope and attribution window.
- ROAS measures revenue efficiency, not profit.
Worked example
Advertising spend of $5,000 produces $20,000 of attributed revenue, so ROAS is 4.0×. If delivery or product cost is $7,000, modeled contribution after ad spend and that cost is $8,000. Other operating expenses are still not included.
Scenario comparison
$5,000 ad spend producing $20,000 attributed revenue gives 4.0x ROAS.
At 30% gross margin, that revenue creates about $6,000 gross profit before other costs.
How to interpret the result
A break-even ROAS depends on contribution margin. A low-margin product needs a higher ROAS than a high-margin product to cover advertising. Refunds, discounts, agency fees, creative cost, and delayed repeat purchases may also change the economics.
Compare ROAS with CAC, conversion rate, new-customer mix, and contribution profit. Optimizing only platform ROAS can shift spend toward customers who would have purchased without the ad.
What a good result looks like
A sustainable ROAS must clear the break-even level implied by margin, refunds, fees and other variable cost.
A very high ROAS is not automatically best if volume cannot scale.
Common mistakes
- Comparing platforms with different attribution settings as if their reported revenue is identical.
- Using ROAS as a substitute for contribution profit.
When this metric can mislead you
Platforms can double-count the same conversion.
Short-term ROAS can undervalue repeat-purchase campaigns or overvalue demand capture.
How to use the result in a decision
Use ROAS to manage campaign efficiency, then connect it to margin, CAC and LTV.
Set a break-even ROAS before scaling spend.
Assumptions and limitations
- Attributed revenue and ad spend cover the same campaign and period.
- The selected attribution model is applied consistently.
- Entered delivery cost excludes ad spend to prevent double counting.
- The contribution result excludes unentered operating expenses and tax.